Visibility of Lights, ContinuedUnderstandingThere are several terms associated with any lights visibility. Figure 4-3thewill help you to visualize the relationships existing among these terms asRelationshipsthey apply in a situation in which an observer with a height of 50 feet isAmong Termslocated exactly at the computed range to a light having a geographicrange of 11.7 miles and a nominal range of 15 miles. Review figure 4-3and the associated terms list on the next page.Figure 4-3. Relationship of light visibility terms.4-9